a. Field of the Invention
The present invention relates to an electronic calculator particularly suitable for educational purposes.
b. Description of Prior Art
Conventional types of portable electronic calculators have been intended for arithmetical results to be obtainable by any one, even a child or unskilled person, through simple operations for arithmetical calculations such as addition, subtraction, multiplication, division, etc.
FIG. 1 is a perspective illustration of a small-sized electronic calculator, wherein a refers to the conventional numerical key group which inputs digits 0-9 and decimal points, while b refers to the conventional function key group which provides instructions and directions for execution thereof. By actuating said function key group b, the four arithmetical operations, etc., are executable on the operators and operands which have been inputted by depressing the relevant keys of the numerical key group a.
For instance, if one operates the calculator to calculate 123.times.24, the keying procedure as illustrated below is required. EQU [1]--[2]--[3]--[.times.]--[2]--[4]--[=]
Through this keying procedure, the arithmetic result for the imparted numerical numbers is displayed in the display unit as shown in FIG. 2.
Accordingly, the results of calculation are obtained by so-called one-touch, or reduced, operations, which means, however, that the calculation processes i.e., details of the calculation methods, are not understandable, and therefore these conventional types of calculators are not desirable for primary and junior high school pupils from the educational point of view.